Hmm... I'm gonna pick a Charmander in Pokemon X, but I will not use that Charmander, I will use one that was migrated from Kanto! {XD) BUT that will be in post-E4. As I said earlier, non-native Pokemon will not be part of my party. :P
How do you build your party? Mostly I have 3-5 members they are consisted with Pokemon that can use the following types: Grass, Water, Fire, Electric, Ground and Ice moves. At least one Physical attacker and one Special attacker. Neat eh?:)